Polyesters particularly suitable for use in coating compositions which are sprayed with compressed fluids as vicosity reducing agents

A process for the liquid spray application of coatings to a substrate containing one or more polyesters which comprises:

• a) forming a liquid mixture in a closed system, said liquid mixture comprising:
• i) at least one or more polyesters comprising the reaction product of (i) a liquid hydrocarbon diol comprised of primary hydroxyl groups and 8 or more carbon atoms in which the primary hydroxyl groups are separated by 4 or more carbon atoms linearly arranged and in which at least one of said carbon atoms linearly arranged is a disubstituted carbon atom or at least 2 of said carbon atoms linearly arranged are monosubstituted carbon atoms, said liquid hydrocarbon diol represented by the formula:
• ##STR12## wherein R.sub.1 is hydrogen or linear or branched alkyl having from 1 to 3 carbon atoms, and R.sub.2, R.sub.3 and R.sub.4 are the same or different and are hydrogen or linear or branched alkyl having from 1 to 4 carbon atoms, said liquid hydrocarbon diol existing as a liquid at a temperature of 35.degree. C. or less, and/or a derivative of said liquid hydrocarbon diol, provided when said polyester is an unsaturated polyester, then said liquid hydrocarbon diol is other than 2,4-diethyl-3-propyl-1,5-pentanediol, and (ii) a polyfunctional carboxylic acid and/or an acid anhydride;
• and
• ii) at least one compressed fluid in at least an amount which when added to (i) is sufficient to render the viscosity of said mixture less than about 150 centipoise, wherein the compressed fluid is a gas at standard conditions of 0.degree. C. and one atmosphere (STP);
• and
• b) spraying said liquid mixture onto a substrate to form a liquid coating thereon.